I have a 2011-03 kept up to date, and currently running aptosid's 3.8.0 kernel. I don't know exactly when it started as it took me a while to figure it out, but about a month ago, after doing a DU my fan would switch off and would not come on as soon as kernel loaded. The kernel that comes with 2012-01 (3.6.8 ) seems to be working fine (so possibly starting from 3.7.x). Debian Sid's 3.2.0 kernel is working fine as well. My laptop is quite old Compaq NC8230 with Pentium M.